To dynamically update their location, many mobile wireless devices use on-board global positioning system (GPS) technology. GPS technology can allow a mobile wireless device to accurately calculate its geographical location. However, for those mobile wireless devices that do not have a GPS component or other method of determining geographic location, useful approaches to determine a geographic location may be limited. In addition, even in phones with GPS capability, devices may frequently have their location determination capabilities interrupted by so-called “urban canyons” or other obstructions. GPS location determinations are also subject to errors. Because GPS determinations also consume significant amount of battery, some mobile application developers seek to use it sparingly.
To provide location estimates to mobile devices, it can be useful to know the locations of wireless access points. Estimating the location of mobile devices and wireless access points can be difficult.